|Subject:||Use of $& slows down all programs using DateTime::Format::Duration|
DateTime::Format::Duration line 597: croak("Unknown symbols in parse: $&") if $field_list=~/(\%\w)/g; (I'm pretty sure the /g flag is wrong here, but that's not the point.) This line uses the special variable $& which slows down all regex matches in all programs that (directly or indirectly) use this module. Seefor details. Simply changing $& to $1 in that line improved the runtime of a particularly regex-heavy program from 23s down to 15s. It would be good if you could make that change to the official release on CPAN.